Lenovo Legion 5 15ARH05H, NM-D281 Rev: 1.0 not work with the battery

[MTT97]

I think I found the rootcause. Its a PU2001 (RT6585CGQW - 3Vand5V driver) + speciific PwrSeq on this board. This chip is damaged in specific way. There is leak of voltage to the ugate + shorted Ugate and source of Hiside mosfet (PQ2001) on 3VALW rail. So at the end you have follow situation:
- When MB is powered by battery only there is a leak on 3VALWS and I have there 1.2V.
- With the charger this leak is 3.4V which is really close what you should get on this rail.
According to PwrSeq. with battery only for S5 stage, 3V and 5V ALW is OFF. S5 stage with charger, 3V and 5V ALW is ON and here I think is the reason why MB did not detect this specific short when powered with charger cause EC immediately send EN signal for PU2001 for 3V and 5 ALWS + the leak is very close to the nominal voltage on this rail and it is not detect or the current sens in the charger circuit is less sensitive than the battery one. PGOOD is pulled up to 3ALW.

I will confirm that when Richtek arrives and I will be back from vacation.

RT6585BGQW is the first thing in my suspect list to replace, followed by BQ24780SRUYR. When i received the laptop and plugged in the charger, i noticed that the RT6585BGQW was getting immediately hot, way too hot to even touch. It didn't take me long to find out that the +3VLP was shorted to ground. I then removed EC > short was gone > replaced EC > still no short > laptop now comes on but wont work if battery is plugged in.

[abobek zum]

I think I found the rootcause. Its a PU2001 (RT6585CGQW - 3Vand5V driver) + speciific PwrSeq on this board. This chip is damaged in specific way. There is leak of voltage to the ugate + shorted Ugate and source of Hiside mosfet (PQ2001) on 3VALW rail. So at the end you have follow situation:
- When MB is powered by battery only there is a leak on 3VALWS and I have there 1.2V.
- With the charger this leak is 3.4V which is really close what you should get on this rail.
According to PwrSeq. with battery only for S5 stage, 3V and 5V ALW is OFF. S5 stage with charger, 3V and 5V ALW is ON and here I think is the reason why MB did not detect this specific short when powered with charger cause EC immediately send EN signal for PU2001 for 3V and 5 ALWS + the leak is very close to the nominal voltage on this rail and it is not detect or the current sens in the charger circuit is less sensitive than the battery one. PGOOD is pulled up to 3ALW.

I will confirm that when Richtek arrives and I will be back from vacation.

[MTT97]

So, for 230W, the measurement is correct; for 180W, it is not. However, I think there is no point in focusing on the charger anymore. Try doing what Mon2 suggested, and perhaps you will notice some anomaly.

In my case, which could also be helpful for you, I was focusing on the SMBUS between the EC, the battery, and the BQ. I posted all the data that I got (for comparison purposes). I analyzed that data with AI, and it seems to be OK. So, the issue lies somewhere around the BQ chip (HW issue) or in the EC software—where, even if it gets the feedback from the battery, it is not accepting it for some reason (that could be another lead for a potential issue in your case, due to the fact that you replaced the EC chip).

MTT97 , did you program the new EC chip, or did you write it with FF and look for autoprogramming from the main BIOS? I am not familiar with that MB, so I don't know if this EC supports autoprogramming.

As for me, I have already tried two different BIOSes, and I programmed the IT8227E for each case individually. The behavior is the same. Based on that, I will focus on the HW, so now I am going to replace the capacitors and resistors around the BQ chip one by one, including the MOSFETs, even if the measurements are OK for them.
Last resort will be looking for EC dump which works with exactly that type of the battery .....

The IT8226E-192 i got off Ali was already ''pre-programmed'' for my board, so when i soldered it on the board, it did indeed boot but could also been empty and was auto programmed. Yet i bought a cheap programmer off Ali, erased the chip and the laptop was able to auto program the chip by itself but still didn't solve the issue. My final attempt i erased the chip again and had someone to extract the EC file from the bios and then written it manually into the EC chip but same issue as before again. I spent a lot of time and money on this board which doesn't even have great specs tbh (i5 9300h + 1660ti), i'm waiting for a new multimeter, other equiptment before i continue this repair just a bit more before moving on.

[abobek zum]

So, for 230W, the measurement is correct; for 180W, it is not. However, I think there is no point in focusing on the charger anymore. Try doing what Mon2 suggested, and perhaps you will notice some anomaly.

In my case, which could also be helpful for you, I was focusing on the SMBUS between the EC, the battery, and the BQ. I posted all the data that I got (for comparison purposes). I analyzed that data with AI, and it seems to be OK. So, the issue lies somewhere around the BQ chip (HW issue) or in the EC software—where, even if it gets the feedback from the battery, it is not accepting it for some reason (that could be another lead for a potential issue in your case, due to the fact that you replaced the EC chip).

MTT97 , did you program the new EC chip, or did you write it with FF and look for autoprogramming from the main BIOS? I am not familiar with that MB, so I don't know if this EC supports autoprogramming.

As for me, I have already tried two different BIOSes, and I programmed the IT8227E for each case individually. The behavior is the same. Based on that, I will focus on the HW, so now I am going to replace the capacitors and resistors around the BQ chip one by one, including the MOSFETs, even if the measurements are OK for them.
Last resort will be looking for EC dump which works with exactly that type of the battery .....

[MTT97]

I meant to measure resistance of ID pin on your charger, not on your MB. To eleminate charger.

Two original Lenovo chargers has already been tried, 180W & a brand new 230W charger. Same result.

Edit: 180w & 230w both measured 4.6k

[abobek zum]

The battery doesn't have enough charge to test it if the laptop works on battery only and i have no bench power supply at the moment to charge it manually. The laptop wont charge the battery either, it's just blinking orange light.

As for ADAPTER_ID, the resistance to ground measured 950ohm which was low, i then removed the PD203 diode as mentioned before and now ADAPTER_ID is measuring 6k ohm to ground.

I meant to measure resistance of ID pin on your charger, not on your MB. To eleminate charger.

[MTT97]

Small update. Battery is not the solution for my case. I tested with 3 different batteries.
MTT97, is your laptop starts only on battery ? Your desciption when you plugin charger and battery is the same as main.

About the warrning, you should measure the resistance on adapter pin and ground on your charger. How many Watts you should have there ?
Here are few values.
170 W ~ 1,9 kΩ

230 W ~ 4,6 kΩ

300 W ~ 8,6 kΩ

P.S you have diffrent laptop/ MB so you should probably start your own thread.

The battery doesn't have enough charge to test it if the laptop works on battery only and i have no bench power supply at the moment to charge it manually. The laptop wont charge the battery either, it's just blinking orange light.

As for ADAPTER_ID, the resistance to ground measured 950ohm which was low, i then removed the PD203 diode as mentioned before and now ADAPTER_ID is measuring 6k ohm to ground.

[mon2]

but i still cannot get the laptop to boot with battery and charger plugged in.

MTT97 - this usually implies that you have leaky mosfet in the power path.

Remove all power -> meter in resistance mode -> review the measurements across the 2nd DCin mosfet @ PQ102:

source / drain
source / gate
gate / drain

Post each measurement. Each should be hundreds of k ohms or higher else is likely defective and should be replaced. If found to be ok, review the other mosfets linked to the charger IC. Suggest to review PQ103 next (aka battery mosfet).

As per the charger article by piernov (see above for this sticky), often the 2nd DCin mosfet becomes defective and raises such issues. If available, flux and replace PQ102 for quick testing. These are common N-channel mosfets and may be available on assorted motherboards.

[abobek zum]

Small update. Battery is not the solution for my case. I tested with 3 different batteries.
MTT97, is your laptop starts only on battery ? Your desciption when you plugin charger and battery is the same as main.

About the warrning, you should measure the resistance on adapter pin and ground on your charger. How many Watts you should have there ?
Here are few values.
170 W ~ 1,9 kΩ

230 W ~ 4,6 kΩ

300 W ~ 8,6 kΩ

P.S you have diffrent laptop/ MB so you should probably start your own thread.

[MTT97]

I have pretty much the same issue as OP. Laptop is legion y540 15irh, boardmodel NM-C221. The EC was bad causing the +3VLP on PU601 to short to ground. Replaced EC, short gone, laptop comes back to life. But i'm now seeing a warning message on each boot that You are using a lower-wattage adapter and when battery is connected with the charger, it wont boot at all. The charger led blinking orange and power button blinking white. I removed the PD203 diode for the Adapter_ID and the low wattage adapter warning is now gone but i still cannot get the laptop to boot with battery and charger plugged in. There are voltage fluctuation when the battery and charger plugged in at the same time, i've done a lof of measurement, including some here:


Battery + charger:
780s_VCC = stable 20v / internal resistance when everything unplugged 500ohm

BQ24780S_VDD = stable 5.7v / internal resistance when everything unplugged 430ohm

PC216 780S_LX = unstable 4.3-1.6v

PC216 780S_BS_R = unstable 8-3v

PR211 780S_BS = unstable 9-3v


Battery only:
780s_VCC = stable 11v

BQ24780S_VDD = stable 5.9v

PC216 both pins = stable 11v

PR211 both pins = stable 11v


Charger only:
PC216 780S_LX = 0.2v stable

PC216 780S_BS_R = 5.6v stable

PR211 780S_BS =5.6v stable

Everything else seems to be stable

[mon2]

RTC battery MUST be connected and must be ~3V else needs to be replaced. This is the first required step of the power on cycle on most motherboard designs.

The mosfet readings are correct. From the details so far, to me, the battery is the root cause and should be replaced with a known fresh one. If done already, test with another brand. There are many bad batteries on the market. The specs of the batteries can be faked with simple I2C tools from TI, etc. There are at least 2 companies selling devices to 'unseal' batteries, etc. To me, it is illogical to pimp up a dead battery. If the BMS locked out the battery pack, it did so for safety reasons. Forcing the BMS to come back to life again with hack tools is dangerous.

[abobek zum]

Battery only:
REGN is floating from 0.2V - 07V. If your press the PWRBTN, the MB is coming ON for split second and turining off. During this time REGN goes to 6.1V (same voltage as with charger only)

Battery plug in + charger:
PQ103 D: 20,54V, S:16,41V G:16,40V
PQ102 D: 20,44V, S: 20,44V G: 26,33V
PU101 Pin28: 19,19V

Here the boot is cycling - MB is coming ON and OFF. When I diconnected the SDA and SCL from battery (remove the PR205, PR206). I can boot this MB in this configuration, unplugin the charger and MB remains ON but if turned off it will not start with battery only. You need repeat the sequence with the charger. RTC battery is awlays not connect during this tryouts

[mon2]

These are ok measurements.

Still with only the battery, review the REGN pin on the charger IC.

Next, attach the adapter and measure these points again:

PQ103 D: 16.34V, S:16,34V G:22,42V
PQ102 D: 16,34V, S: 0V G: 0V
PU101 Pin28: 16,16V

[abobek zum]

Hi Mon2,

Here are the measurement"
PQ103 D: 16.34V, S:16,34V G:22,42V
PQ102 D: 16,34V, S: 0V G: 0V
PU101 Pin28: 16,16V

[mon2]

Attach the pre-charged battery only; disconnect the power adapter.

Meter in DC volts (30v or higher) scale.

Measure the voltage to ground of the following points of interest:

PQ103 (battery mosfet) ; source - drain - gate pins are of interest
PQ102 (DCin mosfet) ; source - drain - gate pins are of interest
PU101 pin 28

[abobek zum]

abobek zum - each case is different. Post the full details of your issues.

Thank you for your prompt answer.
In fact I have exactly same issue with the specific behavior included as OP so rather to create new topic I just want to ask about the status from this one. Tested on 2 different batteries ( one replacement and second one looks line original but have very few Charge/discharges count so probably is also not the original from that laptop - check by SVOD) - same effect. On other forum I found that solution was to use the Original battery.

[mon2]

abobek zum - each case is different. Post the full details of your issues.

[abobek zum]

HI,

would like to bump this topic even if its quite old. Was that issue solved ?

[dhs6512]

Measured all signals on the charger BQ24780S, comment please. Thank you.

[dhs6512]

Charged battery (in this unnormal cycle mode) to about 15v and now voltages at PD101: 1pin 780S_VCC_R 14,74v, 2pin VIN 0,002v, 3pin BATT+ 14,93V